In addition to the biological inheritance,families also share cultural and Social inheritance, including diet, life style patterns including exercise, and exposure to similar environmental agents, and pathogens. Any one, or a combination of these factors could just as likely have been the causative agent in sickling. For example, at about this same time (the nineteen-teens and 'twenties) many people in the U.S. and elsewhere suffered from a condition known as pellagra, which was claimed by a major government commission to be hereditary on the basis of pedigree studies. It was subsequently shown that pellagra was the result of a vitamin B1 deficiency, and thus not hereditary at all in the genetic sense. It did run in families, however, due to dietary practices which are passed on culturally from parents to children. Thus, the frequency of sickle cell anemia in African Americans in general, or in the C.T. family in particular, tells us nothing necessarily about whether it is a genetically determined condition or not.